Carton opening means



Nov. 5, 1963 w. c. KNIPP 3,109,577

CRTON OPENING MEANS Filed Jan. 17, 1963 2 sheets-sheet 1 ATTORNEY Nov. 5, 1963 w. c. KNIPP CARTON OPENING MEANS 2' Sheets-Sheet 2 Filed Jan. 17, 1965 INVEN TOR.

ATTORNEY United States Patent O 3,i ii9,577 CARMEN GPENHNG MEANS William C. Knipp, Kansas City, Mo., assigner to {american Can Company, New York, NX., a corporation of New Jersey Filed Jan. 17, 1953, Ser. No. 252,2l3 6 Claims. (Cl. 229-5l) This invention relates to a tamperproof opening means for cartons. More specifically, the invention relates to an opening means for a carton employing a reclosable cover or lid.

When employing an opening means on a carton, several features are desirable. The opening means should be essentially tamperproof so that any opening prior to that by the user is readily ascertainable. Also, the means should be easy to open as well as readily accessible. Furthermore, the means employed should not materially weaken the carton construction so as to impair the setting up of the carton blank to form the closed carton. Previous tear strips, such as the one disclosed in US. Patent No. 2,218,509, tend to prevent the proper squaring of a glued carton shell due to the lines of Weakness defining the tear strip acting as fold lines. Instead of the front panel and the front cover panel attached thereto lying in a common plane, the front panel collapses inwardly with the front cover panel positioned at an angle thereto.

The general object of the present invention is to provide an opening means which does not impair the setting up of the carton blank to form a completed carton.

The present invention provides a carton with an opening panel having therein a curved tear strip opening means which, due to the curved lines of weakness defining the strip, resists folding when the carton shell is erected. Since the lines of weakness do not function as fold lines, the front cover panel attached through said tear strip to the front panel remains in essentially parallel relationship with the front panel and the erected carton has the front, bottom, rear and cover panels positioned consecutively at right angles to each other.

Further details and advantages of the invention will be apparent from the following specification and appended drawings, wherein:

FlGURE l is a plan View of an integral blank suitably cut and scored to form a tamperproof carton having a curved tear strip opening means,

FIGURE 2 is a perspective View of the folded blank shown in FIGURE l, partially set up,

FIGURE 3 is a perspective View of a folded partially set up blank similar to thc blank shown in FIGURE 1, but employing a straight tear strip opening means,

FIGURE 4 is a fragmental perspective view of the blank of FiGUilE l at a further stage of erection, and

FGURE 5 is a penpective View of the completed carton showing the cover in closed and sealed condition.

Referring to FlGURE l, the carton Vemployed is made of a single foldable blank of flexible material such as paperboard. The blank is divided by score lines lil-13 and cut lines 19-21 into hingedly connected panels and flaps including opening panel 3d, cover panel 3l, rear panel 32, bottom panel 33, front panel 34, inner end panels 35, outer end panels 36, end flaps 3'7, end cover flaps 33 and cover tabs 39. A tear strip Sb is defined by lines of weakness 22 and Z3 in opening panel 3l?. Lines of weakness 22 and 23 divide opening panel 3@ into a front cover ilap Illia, tear strip Elib and glue flap 3de. The function of 3tlg, 36h and Lilie will be described more fully hereinafter. End cover flaps 33 have extending portions 33a which serve to retain the end cover flaps in the completed unopened carton.

The blank is formed into a glued carton shell by folding front panel dfi about score line i3 to lie directly super- ICC posed on bottom panel 33, applying adhesive on the exposed surface lille and then infolding panels Sil and 31 about score line il so that the adhesive bearing surface overlies and becomes adhered to the exposed surface of panel 34 adjacent its outer free edge. In such condition the collapsed carton shell may be shipped economically to the product packager for setting up, filling and sealing.

FIGURE 2 depicts an initial stage in which the carton is squared and ready for filling. When the shell is squared, panels 3l, 32, 33 and 3d are positioned consecutively at right angles to each other. Opening panel 3d bears the same relation to panels 3l, 32 and 33 as does panel 34 on which it is directly superposed. Itis essential in high speed, machine operation for the proper closure of one end, filling and closing of the other end that the'cartou shell maintain its squared shape after the initial squaring. ln FGURE 3 a carton shell similar in all respects except as to the configuration of the opening panel is shown. The carton shell of FlGURE 3, however, is partially collapsed with the front panel and cover panel at other than a right angle. The partial collapse is caused by either of the lines of weakness 22 and 2.3 acting as fold lines about which the opening panel elements tend to fold at angles to each other. The folding may occur along line 23 between the front cover flap 30a and the tear strip Stili or else along line 22 between tear strip Sllb' and glue iiap 3de. Due to the fact that the lines of weakness 22 and 23' offer less resistance than the fold lines connecting the carton panels, the carton shell of FIGURE 3 fails to assume and maintain the essential squared shape.

ln the carton construction according to the present invention the use of substantially curved or arcuate lines of weakness prevents the lines from functioning as fold lines. The resistance to folding due to the curved shape of the lines is sufficiently great so that the panels fold along the fold lines connecting hem. Upon squaring, the carton shell assumes and maintains the shape shown in FEGURE 2. After equating usually one end is closed, the carton filled, the other end closed and then both ends sealed to form a completed filled carton. Since the closing and sealing steps for both ends are the same, reference is had to closing just one end of the carton.

In closing the carton after filling, inner end panel 35 is folded inwardly about score line ld to a position perpendicular to front panel 34. Then end iiap 37 and cover tab 39 are folded inwardly about score lines lo and i3, respectively, to overlie inner end panel 35. Adhesive is applied to the outer exposed surfaces of inner end panel 35, end flap 37 and cover tab 39. The adhesive pattern is applied so that when outer end panel 36 is infolded, the upper marginal edge portion remains unadhered. End cover flap 3b is then folded inwardly about score line l? and adhered to cover tab 39 to give the configuration shown in FIGURE 4. To complete the closing, outer end panel 3d is folded inwardly about score line l5 and adhered to the adhesive bearing surfaces of end flap 37 and inner end panel 3S. The completed carton as it appears to the consumer prior to opening, is shown in FIGURE 5. ln the opened carton the portions 38a of the end cover flaps are held in frictional contact between outer end panels 3o and end flaps 37. Alternatively, the sealing of the carton may be accomplished by pre-applying a hot melt adhesive composition in the desired areas of the carton blank prior to the forming of a carton shell. The carton is then sealed by passing the blank through carton forming and erecting machinery utilizing heaters to reactivate the pre-applied adhesive. adhesive, the panels are infolded and adhered together as described previously. It is obvious that the adhesive can be employed on either of two surfaces to be adhered together.

ln opening the carton the tear strip Elib is grasped at Upon reactivation of the one end and pulled outwardly toward the other end of the package. The particular pattern of the lines ot' Weakness, namely 22 and 23, may be varied so the strip can be removed by starting at either end of the carton. In order to reach the contents of the carton, after detaching the tear strip Seb, it is merely necessary to lift upwardiy at one of the front corners of the cover portion.

When the carton is opened to expose the contents,

,opening panel Sil has been divided by the removal of tear strip St'b into a front cover iiap Sila attached to cover panel 31 and a glue ap Stic adhered to the front panel 34. In the opened carton, the receptacle portion comprisesy front panel 34, bottom panel 33, rear panel 32, inner end panels 35, outer end panels 36 and end aps 37. y The cover portion includes cover 'panel 3d, iront cover ap 30a. and end cover iiaps 3S. ySince the coverflaps areV connected at the -front corners, there are no loose flaps projecting Vfrom the lateral edges of the cover panel when the carton is opened. In reclosing the carton, the cover portion is merely lowered and telescoped over the receptacle portion. The necessity of reinserting the end 1cover flaps is obviated and the package appearance is `essentially the same as prior to openmg.

The employment of the opening means according to the present invention, shown in FIGURES 1, 2, 4 and 5 insures theproper squaring and maintenance of the squared shape of the carton shell Vfor high speed automatic machine operation. The carton may be readily filled and `closed by existing machinery without additional rnodicatfions to insure complete and eiicient operation. The carton formed by `filling, closing and sealing the carton shell is tamperproof and cannot be opened without a tearing of the carton elements. it is to be understood that the description of the carton construction given herein is merely illustrative of the essential Afeature of the invention, and is not limited to the speciiic dimensions yor contours which may be greatly varied or modified and whchvariations are intended to be inledge by a substantially curvilinear line of Weakness to said cover portion and along the other edge by a sublines of weakness into (1) said front cover iiap (2) a'- tear strip intermediate said lines of weakness and (3) an adhesive `flap 4adhered to said front panel.

3. An opening means `for a tubular carton, kthe carton including front, rear and bottom panels, and a cover portion; said opening means comprising a tear stripA detac ably connected along one edge by a lineof weakness to" said cover portion and along the other edge by a line of-V weakness to a ap adhered to said `front panel, said lines of weakness being substantially curvilinear and equidis-V tant from eac'n otherthroughout their entire length.

4. A tamperproo, reclosable carton formed of a single blank suitably cut and scored to provide a receptacle portion having an opening at the top thereof and a hinged" box-like cover portion telescoped over the open top of the receptacle portion; said receptacle portion comprising a front panel, a bottom panel, a rear panel and end panels, said cover portion comprising a rear panel hingedly connected to the upper edge of said rear receptacle panel, a top cover panel, a front cover yflap and end cover aps; a tear strip detachably connected along one edge by a substantially curvilinear line of weakness to said` front cover ilap and along the other edge by a substantially curvilinear line of weakness to a -ilap adhered to said front panel.

5. The carton of claim 4 4wherein the linesV of weak-V ness are equidistant 'from each other throughout their entire length.

6. The opening means of claim 3 wherein the tear `strip extends for the full length of the cover portion and is of narrow width relative to the Width of the cover panel.

References Cited in the file of this patent UNITED STATES PATENTS Mai June 8, 1954 Arneson Jan. 30,1962 

1. AN OPENING MEANS FOR A TUBULAR CARTON HAVING FRONT, REAR AND BOTTOM PANELS AND A COVER PORTION; SAID MEANS COMPRISING A TEAR STRIP DETACHABLY CONNECTED ALONG ONE EDGE BY A SUBSTANTIALLY CURVILINEAR LINE OF WEAKNESS TO SAID COVER PORTION AND ALONG THE OTHER EDGE BY A SUBSTANTIALLY CURVILINEAR LINE OF WEAKNESS TO A FLAP ADHERED TO SAID FRONT PANEL. 